These speakers are great, I don't think you could get a better 5.1 set for the price, period. Actually, idk if you could get a better 5.1 for 150% of the price. So, how should you take that? Easy, if you want a great system and not want to spend 150+ then get this, you won't be upset with the decision at all.

No idea when these were added. I don't use them much, mostly just the headphones, but they sound decent, and haven't given me any trouble. Sound isn't as crisp as I would like, but I'm spoiled by my Sennheisers

Shocking sound performance at a jaw dropping value. This will ruin any sound system below a 5.1 sound system for you. :)

If you are new to 5.1 audio, the instructions are minimal for the correct plugins.
Consult your motherboard manual on setting up 5.1 speakers, and there are also helpful guides on the internet for identifying what each color cable does when doing true 5.1 audio. Have a game that supports true 5.1 (Valve games like Garry's Mod and Left 4 Dead 2 work great; configure 5.1 audio under settings) to test and make sure it works.